Siegel V, Walter P
Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0448.
Cell. 1988 Jan 15;52(1):39-49. doi: 10.1016/0092-8674(88)90529-6.
Signal recognition particle (SRP), a small ribonucleoprotein required for targeting secretory proteins to the ER, has three known functions: signal recognition, elongation arrest, and translocation promotion. Because SRP is inactivated by the sulfhydryl alkylating reagent N-ethylmaleimide (NEM), we have attempted to establish structure-function relationships within SRP by assembling particles in which a single protein is modified. Alkylation of the 68/72 kd protein of SRP yields a particle that arrests elongation but fails to promote translocation and no longer interacts with SRP receptor. Alkylation of the 54 kd protein yields a particle that fails to recognize signal sequences. This approach has allowed us to map activities to specific protein domains on SRP, and should be generally useful for analyzing other ribonucleoproteins.
信号识别颗粒（SRP）是一种将分泌蛋白靶向内质网所需的小核糖核蛋白，具有三种已知功能：信号识别、延伸阻滞和易位促进。由于SRP会被巯基烷基化试剂N - 乙基马来酰亚胺（NEM）灭活，我们试图通过组装单个蛋白质被修饰的颗粒来建立SRP内的结构 - 功能关系。SRP的68/72 kd蛋白烷基化产生一种颗粒，该颗粒会阻滞延伸，但无法促进易位，并且不再与SRP受体相互作用。54 kd蛋白烷基化产生一种颗粒，该颗粒无法识别信号序列。这种方法使我们能够将活性定位到SRP上的特定蛋白质结构域，并且通常可用于分析其他核糖核蛋白。
